Gao Xiang, LaValley Michael P, Tucker Katherine L
Jean Mayer USDA Human Nutrition Research Center on Aging, Tufts University, Boston, MA 02111, USA.
J Natl Cancer Inst. 2005 Dec 7;97(23):1768-77. doi: 10.1093/jnci/dji402.
The Dietary Guidelines for Americans 2005 recommends that Americans increase their intake of dairy products. However, some studies have reported that increasing dairy product intake is associated with an increased risk of prostate cancer. We conducted a meta-analysis to examine associations between intakes of calcium and dairy products and the risk of prostate cancer.
We searched Medline for prospective studies published in English-language journals from 1966 through May 2005. We identified 12 publications that used total, advanced, or fatal prostate cancer as end points and reported associations as relative risks (RRs) with 95% confidence intervals (CIs) by category of dairy product or calcium intake. Data were extracted using standardized data forms. Random-effects models were used to pool study results and to assess dose-response relationships between dairy product or calcium intakes and the risk of prostate cancer. We conducted sensitivity analyses by changing criteria for inclusion of studies or by using fixed-effects models. All statistical tests were two-sided.
Men with the highest intake of dairy products (RR =1.11 [95% CI = 1.00 to 1.22], P = .047) and calcium (RR = 1.39 [95% CI = 1.09 to 1.77], P = .018) were more likely to develop prostate cancer than men with the lowest intake. Dose-response analyses suggested that dairy product and calcium intakes were each positively associated with the risk of prostate cancer (Ptrend = .029 and .014, respectively). Sensitivity analyses generally supported these associations, although the statistical significance was attenuated. The pooled relative risks of advanced prostate cancer were 1.33 (95% CI = 1.00 to 1.78; P = .055) for the highest versus lowest intake categories of dairy products and 1.46 (95% CI = 0.65 to 3.25; P > .2) for the highest versus lowest intake categories of calcium.
High intake of dairy products and calcium may be associated with an increased risk of prostate cancer, although the increase appears to be small.
《2005年美国膳食指南》建议美国人增加乳制品的摄入量。然而，一些研究报告称，增加乳制品摄入量与前列腺癌风险增加有关。我们进行了一项荟萃分析，以研究钙和乳制品摄入量与前列腺癌风险之间的关联。
我们检索了Medline数据库，查找1966年至2005年5月期间发表在英文期刊上的前瞻性研究。我们确定了12篇以前列腺癌总发病率、进展期或致命性前列腺癌为终点，并按乳制品或钙摄入量类别报告关联为相对风险（RRs）及95%置信区间（CIs）的文献。使用标准化数据表格提取数据。采用随机效应模型汇总研究结果，并评估乳制品或钙摄入量与前列腺癌风险之间的剂量反应关系。我们通过改变纳入研究的标准或使用固定效应模型进行敏感性分析。所有统计检验均为双侧检验。
乳制品摄入量最高的男性（RR =1.11 [95% CI = 1.00至1.22]，P = .047）和钙摄入量最高的男性（RR = 1.39 [95% CI = 1.09至1.77]，P = .018）比摄入量最低的男性患前列腺癌的可能性更大。剂量反应分析表明，乳制品和钙摄入量均与前列腺癌风险呈正相关（Ptrend分别为.029和.014）。敏感性分析总体上支持这些关联，尽管统计学显著性有所减弱。对于乳制品摄入量最高与最低类别，进展期前列腺癌的合并相对风险为1.33（95% CI = 1.00至1.78；P = .055）；对于钙摄入量最高与最低类别，合并相对风险为1.46（95% CI = 0.65至3.25；P > .2）。
高乳制品和钙摄入量可能与前列腺癌风险增加有关，尽管这种增加似乎很小。
